PHOTOCHROMIC 2H-CHR0MENES ANNELATED AT C5-C6 AND THEIR METHODS OF PREPARATION

摘要

Described herein are C5-C6 annelated naphthopyrans that possess at least one electron-withdrawing group. The compounds possess desirable properties such as increased fading kinetics. Also described herein are new methods for synthesizing 2H- chromenes annelated at C5-C6. The methods involve less stringent reaction conditions as well as provide increased reaction yields. The methods permit the synthesis of a wide variety of substituted naphthopyrans that can be temperature sensitive, which was not possible with previous synthetic routes.